The Fractured Landscape of 215 AD

The autumn of 215 AD found China’s Three Kingdoms in a precarious balance. Sun Quan, ruler of Eastern Wu, retreated to his capital after a disastrous northern expedition, licking his wounds. Meanwhile, Cao Cao, now the self-proclaimed King of Wei, celebrated his recent conquest of Hanzhong with wine and revelry. In the west, Liu Bei—the ambitious leader of Shu—seethed with frustration after losing territory to Sun Quan while his sworn brother Guan Yu began constructing an imposing fortress along the Yangtze.

This period marked a critical juncture where every major player except Sun Quan had clear strategic objectives. Liu Bei pushed his chancellor Zhuge Liang to replenish their depleted coffers; Guan Yu taunted Sun Quan with his growing military installations; and Cao Cao, fresh from his Hanzhong campaign, saw an opportunity to finally crush Wu.

Cao Cao’s Winter Offensive (216 AD)

In late 216 AD, Cao Cao launched a winter campaign against Sun Quan, capitalizing on low water levels that hindered naval defenses. Unlike previous confrontations where Sun Quan could afford bold naval maneuvers, this battle at Ruxukou proved disastrous for Wu. Forced into submission, Sun Quan did what he had done many times before—he surrendered.

Cao Cao, overjoyed at this political victory, withdrew after just two months. He returned to his capital to adopt imperial regalia—twelve-jeweled crowns, golden chariots drawn by six horses—effectively completing his transformation into a de facto emperor. Meanwhile, Sun Quan endured humiliation on multiple fronts: submitting to Cao Cao in the north while watching Guan Yu’s fortress at Jiangling grow ever more formidable.

The Powder Keg Ignites (217-218 AD)

By late 217 AD, tensions reached a boiling point. Zhang Fei and Ma Chao launched a northern expedition against Wudu, marking the prelude to the climactic Battle of Hanzhong. Then, in early 218 AD, a rebellion erupted in Xuchang. Officials including Geng Ji and Wei Huang plotted to kidnap Emperor Xian and deliver him to Liu Bei’s forces. Though poorly executed, the coup revealed two critical developments:

1. Rebels believed linking with Guan Yu in Jing Province offered their best chance of success
2. Guan Yu’s military reputation had grown so formidable that even distant Xuchang trembled at news of his movements

As Liu Bei’s forces bogged down at Yangping Pass, unrest spread westward. In Luoyang, peasant leader Sun Lang revolted against oppressive corvée labor, receiving military support from Guan Yu to wage guerrilla warfare. By July 218 AD, when Cao Cao marched west to confront Liu Bei, another rebellion exploded in Wancheng.

The Wancheng Uprising: A Missed Opportunity

The Wancheng revolt under Hou Yin presented Guan Yu with a golden opportunity. As the rebel leader declared: “The people of Nanyang have suffered under Cao’s rule! When Cao’s army arrives, Guan Yu’s forces will meet them!” This belief—that Guan Yu could match Cao Cao’s main army—demonstrated the awe surrounding the Shu general.

Yet Guan Yu held back. Three strategic considerations stayed his hand:
1. Keeping Cao Cao’s forces divided between Hanzhong and Wancheng served Shu’s broader interests
2. Winter’s low water levels disadvantaged his river-based forces
3. Engaging Cao’s elite central army on dry land risked catastrophic defeat

This restraint, while tactically sound, allowed Cao Cao to crush the Wancheng rebellion by early 219 AD—just as Liu Bei achieved his decisive victory at Mount Dingjun, killing Xiahou Yuan.

The Tide Turns (Spring-Summer 219 AD)

With Cao Cao forced to retreat from Hanzhong, Guan Yu launched his long-awaited northern campaign. By May 219 AD, he had advanced to Fancheng, where historical records—written from Wei’s perspective—conspicuously omit details of engagements between Guan Yu and Cao Ren. The omissions speak volumes: Wei’s chroniclers had nothing glorious to report.

By July, the situation grew so desperate that Cao Cao dispatched Yu Jin with 30,000 reinforcements. Meanwhile, Liu Bei returned to Chengdu after declaring himself King of Hanzhong—a fateful decision that removed psychological pressure from Cao Cao. The Wei king, no longer fearing a Shu offensive from the west, could now focus entirely on the eastern front.

The Climax and Collapse

What followed became legend. During the autumn floods of 219 AD, Guan Yu’s river navy achieved what seemed impossible—using the swollen Han River to isolate and overwhelm Yu Jin’s relief force. Contemporary accounts describe the terror:

“Guan Yu is swift and fierce as a tiger! He strikes where advantage lies!” warned Yang Province Inspector Wen Hui, who dismissed Sun Quan’s simultaneous attack on Hefei as insignificant compared to the Guan Yu threat.

Yet this zenith contained the seeds of downfall. Liu Bei’s absence from Hanzhong allowed Cao Cao to concentrate all resources against Guan Yu. Worse still, Sun Quan—long humiliated by Guan Yu’s fortifications—chose this moment to betray their alliance.

Legacy of a Campaign

The 215-219 campaigns demonstrated:
– Guan Yu’s mastery of river-based warfare that temporarily neutralized Wei’s numerical superiority
– How popular resentment against Cao Cao’s labor policies nearly toppled Wei’s control of central China
– The fatal consequences of Liu Bei’s strategic withdrawal from Hanzhong

Modern historians debate whether Guan Yu overextended or fell victim to circumstances. What remains undisputed is that his campaign marked the last, best chance for Shu to alter the Three Kingdoms’ balance—a moment when one general’s brilliance nearly reshaped Chinese history.